Module: DataMapper::Money::ClassMethods

Defined in:
lib/dm-money.rb

Instance Method Summary collapse

Instance Method Details

#money(name, options = {}) ⇒ Object

Add a BigMoney property.

Parameters

name<Symbol>

Name of the composite money property.

options<Hash(Symbol => String)>

DataMapper property options.

Examples

class Bike

include DataMapper::Resource
# ... other properties.

money :gst
# public
#   gst #=> BigMoney
#   gst=(value)
#
# property :gst_amount,   BigDecimal, accessor: private
# property :gst_currency, String,     accessor: private, length: 3

money :price, required: true, accessor: protected
# protected
#   price #=> BigMoney
#   price=(value)
#
# property :price_amount,   BigDecimal, accessor: private, required: true
# property :price_currency, String,     accessor: private, required: true, length: 3

end – TODO: Validations.

Raises:

  • (ArgumentError) 


41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
 
# File 'lib/dm-money.rb', line 41

def money(name, options = {})
  raise ArgumentError.new('You need to pass at least one argument') if name.empty?

  if default = options.delete(:default)
    raise TypeError.new("Expected BigMoney +default+ but got #{options[:default].class}") \
      unless default.is_a?(BigMoney)
  end

  # TODO: Golf.
  property               = DataMapper::Property::Decimal.new(self, name, options)
  name                   = property.name.to_s
  instance_variable_name = property.instance_variable_name
  name_amount            = "#{name}_amount"
  name_currency          = "#{name}_currency"

  options_amount = options.only(:required, :precision, :scale).merge(:accessor => :private)
  options_amount.merge!(:default => default.amount) if default
  self.property name_amount.to_sym, DataMapper::Property::Decimal, options_amount

  options_currency = options.only(:required).merge(:accessor => :private, :length => 3)
  options_currency.merge!(:default => default.currency.to_s) if default
  self.property name_currency.to_sym, DataMapper::Property::String, options_currency

  # TODO: Access amount, currency via readers or properties?
  # TODO: Validations or error message attempting to set with something other than BigMoney?
  class_eval <<-RUBY, __FILE__, __LINE__ + 1
    #{property.reader_visibility}
    def #{name}
      return #{instance_variable_name} if defined?(#{instance_variable_name})
      return unless #{name_amount} && #{name_currency}
      #{instance_variable_name} = BigMoney.new(#{name_amount}, #{name_currency})
    end

    #{property.writer_visibility}
    def #{name}=(value)
      raise TypeError.new("Expected BigMoney +value+ but got \#{value.class}") unless value.kind_of?(BigMoney)
      self.#{name_amount}       = value.amount
      self.#{name_currency}     = value.currency
      #{instance_variable_name} = value
    end
  RUBY
end